Mechanical stoker



Aug. 13, 1935. A. M. HUNT MECHANICAL STOKER Original Filed Dec. 20, 1923 5 Sheets-Sheet l KQQ R mm WM WW 7 v m n AM Y6 B a 6 N ATTORNEY Oyiginal Filed-Dec. 20, 1923 s Sheets-Sheet 2 IN VEN TOR AndrewM. Hunt A TTORNEY Aug. 13, 1935.

A. M. HUNT MECHANICAL S TOKER Original Filed Dec. 20', 1928 3 Sheets-Sheet 3 INVENTOR An dreWM. Hunf ATTORNEY Patented Aug. 13, 1 935 UNITED STATES eArENr OFFICE MECHANICAL sroKEn Andrew M. Hunt, San Francisco, Calif., assignor to The Standard Stoker Company, Incorporated, a 'corporat'ion of Delaware Application nc mberflzo, 1928, Serial No. 327,260

Renewed January 12, 1935 4 Claims. (01. 11 -101) r This invention relates tostokers in general and especially to mechanicalstokers for locomotives; and has faorits principal object the provisionof a simplified, improved type of stoker which delivers the fuel continuously to a firebox, and. in which the fuel is convey-ed from a fuel bin to an elevator member which acts directly to discharge; or projeot the fuel over the firebed. a V

Anotherobiect of the invention is theprovision of {118W and improved mechanical means for dis tributing the fuel .over' the furnace or firebox as it is being projected thereinto.

l Further objects and advantages of the inven tion will be apparent from the followingdescrip tionread' in connection With-the accompanying drawings, in which l l m ,1, iglwl is a central longitudinal vertical section through the stokingapparatus and portions of the I locomotive and tender;

' Fig. 2 is a plan view corresponding to Figure 1 withsome-portions broken away and other parts removed; a

ion, the line 3-3 of Figure 1;

to abnormal stresses resulting in excessive wear of the parts or necessitating the use of additional means for counteracting the stressesset up during operation of the device. Complicated mechanism is many instances required for imparting the desired motion to these parts, which mechanism requires attention and the maintenance is suc that its use is objectionable. i l Byreason ofthe simplicity'of delivery of the stoker of this invention, there is not the necescity for complicated mechanism, nor are the parts subjected to 'severestresses as above described. Its simplicity'of construction, arrangement of its parts and efficient delivery and distributionof the fuel will be observed from the drawings which illustrate the invention as applied toa locomotive and from the following description which describesit as being applied thereto, but it -is; obvious, however, that its isnot to be restrictedto any ordinary or special formof boiler and that it is equally adaptable to other; than locomotive furnaces or fireboxes.

the drawings referring particularly to l figur es l and 2, the illustrated embodiment of this invention is shown as applied to the locomotive, generally indicated at'A, and a tender therefor indicated as a whole at B, the two being connected together for railroad service in the ,5 ordinary manner by an articulated coupling C This illustrated embodiment of the invention is made for the purpose of continuouslyand me- ,chanically conveying the fuel from the fuel bin Hoof thetender to an elevating member I l of 10 thelocomotive which member not only elevates the fuel to a point above the level of the fire, but also acts directly to discharge the fuel into the firebox l2 and over the firebed thereof, preferably, discharging or projecting the fuel through 15 the firing opening l3 of. the backwall Hi, the

distribution to the sides and corners of the firebox being brought about in cooperationwith adjustable deflectors l5, l5a which are so arranged that certain portions of the fuel after leaving theelevating member I l are directed in a manner whereby a uniform distribution over the fire grate i6 is obtained. a

The fuel bin 10 of the tender has a centrally apertured floor provided with slidable plates 18 for forming ,-a shiftable opening through which the fuel is permitted to drop into a transfer conduit, comprising a rearward trough portion [9 and a rigid forwardly extending tubular portion 20, thetransfer conduit being fixedly secured to the, tender below the fuel bin. There is mounted within the transfer conduit aconveyor screw 2! extending through the trough l9 to the forward extremity of the tubular extension 20. The screw 21 may be actuated from the rearward end of its trough portion through suitable gearing by any form of driving motor that will impart, preferably, continuous motion to the screw, although, if desired, the screw may be actuated intermittently, this driving means notbeing shown on these drawings as the construction is known to those familiarwith stoking devices. A crusher member 22 is disposed above'the screw at the forward 'end'of the trough portion I9 for engage- "ment with the larger lumps of fuel being advanced by the screw and is particularly adapted to reduce such lumps to a suitable size for firing. The construction and arrangement of the transfer conveyor is such that it is capable of handling lump, granulated or pulverent fuels with equal efliciency. v 7

As will be best observed from Figures 1 and 2, the rigid tubular portion of the transfer conveyor terminates in the locomotive at a point rearward ,of;the firebox backwall l4 and preferably below the cab fioor 23 of the locomotive cab 24. The forward end of this conduit is unattached and projects into and is partially surrounded by the laterally and vertically flaring lower and open rearward end of a box-like or rectangular shaped elevator casing indicated as a Whole at 25 which comprises side walls 36, Eta, and a bottom wall 23' and a detachable top wall 28 made in the form of a sectional cover which can be removed to give access to the elevator member ll housed therein and mounted for rapid movement as hereinafter more fully described. The casing 25 is suitably supported on the locomotive and secured to the firebox backwall thereof as by the bracket 29 and by suitable bolts through the laterally extending flanges 3%, 38a; of the elevator casing side walls as will be seen from Figure 2. Thus, securing the transfer conveyor commonly referred to as stoker tender unit to the tender and the elevator casing or stoker locomotive unit to the locomo- 'tive firebox and having the parts so arranged that no connections or joints are needed between them, provides a simplified device, the locomotive and tender units of which are unattached and are free to move independently of each other ,to provide for the relative movement that takes place between the locomotive and its tender.

The elevator casing 25 inclines upwardly from below the cab floor and extends forwardly to the firing opening E3 of the firebox and is preferably 'open'to and in communication with the lower portion of said opening, which opening as shown is extended downward somewhatbelow the cab floor in order that the casing will occupy a minimum amount of space within the cab. That portion of the opening it above the top cover 28 of the elevator casing 25 may be closed by any suitable or ordinary form of door or closure not shown, which door may be opened for observation of the fire or for other purposes such as hand firing of the fuel.

From the transfer conveyor the fuel is received by the elevator member II which comprises an endless belt 31 mounted on the separated rollers 32, 33, the rollers being fixed on shafts or axles 3 4 and 35 respectively which are journaled in the side walls Zt, 25a of the elevator casing 25 at different elevations. The rear roller shaft 34 is lower than the forward roller shaft 35 and disposed below the conduit 29 of the transfer convey-or so that the endless belt elevator slants downward from its highest point adjacent to'the firing opening it and is in a position to receive by gravity the fuel from said conduit. Cross bars are angles 35 which are secured to the belt 3i in any desired manner such as by staples or rivets tend to prevent the fuel from rolling backward along the belt and increase its efficiency in elevating the fuel and discharging or projecting 'it into the firebox.

The angle of inclination is such that with a predetermined rate of revolution of the endless delivering the fuel to one portion of the fire independently of the others; this, and the fact that fireboxes vary in length makes it necessary that the discharge of fuel into the firebox may be flexibly controlled, and this is accomplished in the present invention by adjusting the rate of movement of the endless elevator by changing the speed of its drive mechanism to impart the desired velocity to the endless elevator which in turn varies the discharge of the fuel longitudinally of the firebox and which driving mechanism is hereinafter described.

Any motor that will through suitable drive mechanism impart motion of preferably rapid velocity to the endless elevator H may be used with this invention. There is shown for this purpose as will appear on Figures 1 and 2, a motor or if desired a turbine 31 supported as by the bracket 38 to the firebox backwall I4. The motor shaft has mounted thereon a sprocket wheel 39 meshing with an endless chain 4!] which is trained over a sprocket wheel fill of desired proportions and ratio and which is fixed on the roller shaft 35 exterior of the-casing 25 for driving the roller 33 and thus through frictional or if desired, but not shown, sprocket connections drive the endless belt 3|.

The fuel is discharged from the elevator through the opening l3 in the form of a thin layer or ribbon-like stream of a width substan tially equal to the width of the endless belt and it is spread longitudinally over the firebox, its various particles in proportion to their mass dropping onto diiferent longitudinal portions of the firebed. The lateral distribution of the fuel is controlled by a deflecting means, such as manually adjusted deflectors l5, Ida which are disposed above the elevator i l and which may be adjusted so that the vane portion of the deflector may be brought into the path of the fuel and so regulatedas to control and vary the lateral distribution of the fuel. When two such deflectors are used the distribution to either side of the firebox or to the portions thereof may be varied independently.

The deflecting member IE or 95a as best shown in Figures 3 and 4 comprises a bar having a' flattened vane portion 42 at its forward end, curving toward the side wall of the firebox to which it is adapted to direct the fuel, and on its opposite end is formed a ball or spherical knob 43 which isreceived in a ball seat 44 of the casing top cover 28 and held therein by a removable lower half of the seat which may be fastened to the cover portion by any securing means. The seat M is slotted at 55 to permit the desired movement of the deflector in all directions and is also similarly apertured at'46 to permit -movement of-the adjusting lever or handle 41 which handle may be threaded or otherwise fixed to the ball or knob portion on the deflector after it is placed within the seat. The movement of the deflectors l5, We is indicated conventionally on the drawings above referred to, the arrangement being such that an infinite number of positions of the deflectors can be obtained and they may be held in any desired position independently of each other by suitable and novel locking means.

For this purpose a locking plate 43 is mounted around the handle 47, there being sufficient clearance between the handle and plate, but the minimum amount necessary, to permit the plate to move horizontally on the cover 28 regardless of the direction of movement of the handle. The locking plate i8 is apertured at 39 and 49a, an amount necessary to allow its movement about the locking studs 50, 50awhich are in threaded and they are of a size suitable to overlap the apertures 49, 49a in the plate so that portions of the washers will be bearing upon the locking plate 48. By loosening the wing nuts 52, 52a the handle 41 and the locking plate 48 can be moved to the extreme positions of the deflectors l5, la in any direction as controlled by the slotted apertures 45 and it of the ball seat 44, or the deflectors may .be held in any one of infinite intermediate posiand that either may be regulated to assist in controlling the distribution of the fuel as it is being discharged or projected into the firebox by the elevating member ll. Any number of deflectors may be used that will be found suitable for effectively scattering or distributing the fuelover the fire.

From the foregoing description, it will be ob served that the feeding of the fuel and the volume being delivered is separate from and controlled independently of the means for elevating,

discharging or projecting the fuel into and distributing it over the firebed. This independence of operation and the independent adjustable control of the distributing members all combine to provide a flexibly operated stoker which is highly efficient, simple in construction and operation and which continuously, mechanically conveys the fuel to the'firebox and effectively distributes the fuel over the firebed thereof.

idly secured to said trough and extending forwardly therefrom, fuel conveying means disposed in said trough and conveyor casing, fuel elevating means having its lower endbeneath and adjacent the forward end of said conveyor casing and extending forwardly and upwardly therefrom in a substantially straight line, and; a casing rigidly secured to the locomotive enclosing said elevating means and the forward end of said conveyor casing, the communicating ends of said elevating casing and said conveyor casing being free to move independently with respect to each other.

2. In a mechanical stoker, in combination with a furnace having a firing opening therein, a conveyor for transferring fuel from a source of supply to a point rearward of said furnace, an elevator extending upwardly and forwardly from a position immediately beneath the forward end of said conveyor to said firing opening, said elevator being arranged to receive fuel by gravity from the forward end of said conveyor and to convey it to the firing opening, means for operating said elevator at a sufiicient speed to project the elevated fuel through said firing opening vinto said furnace, deflecting means above the path of the projected fuel and extending into the furnace, and means arranged to render said defleeting means adjustable into the path of the projected fuel to a predetermined depth for intercepting the opposite side portions only of the fuel stream and laterally distributing such portions to the sides and back corners of the firebox.

3. In a mechanical stoker, in combination with a locomotive having a'firebox with a firing opening therein and a tender therefor, a conveyor on said tender and extending forwardly therefrom to a point rearward of the firebox of said locomotive, a casing on the locomotive communicating at its rearward end with said conveyor and at its forward end with said firing opening, an endless belt elevator mounted within said casing and extending upwardly and forwardly from a position immediately beneath the forward end of said conveyor to said firing opening, means for imparting motion to said endless belt elevator with suflicient velocity to elevate and project the fuel received from said conveyor into the firebox, de-

flecting means above the path of the projected fuel and extending into the firebox, and means arranged to render said deflecting means adjustable into the path of the projected fuel to a predetermined depth for intercepting the opposite side portions only of the fuel stream and laterally distributing such portions to the side and back ,veyor and elevate it to and project it through said firing opening in a ribbon-like stream, deflecting means above said stream and extending into the firebox and means arranged to render said deflecting means adjustable horizontally and vertically into said fuel stream for assisting in the distribution of the fuel, said conveyor and endless elevating means being operated and said deflecting means being adjusted independently of each other.

ANDREW M. HUNT. 

